EFFECT OF MULTIVALENT CATIONS ON THE ADHESION RATE OF CELLULAR-SURFACES BEARING IONIZABLE GROUPS

The effect of the presence of multivalent cations in a suspension medi um on the rate of adhesion of a charge-regulated cell is investigated theoretically. By using sheep leucocytes as an illustrative example, i t is found that the presence of multivalent cations has the effect of decreasing the rate of adhesion of the cells. On the basis of the conc ept of the Donnan potential, it is found that the magnitude of the ele ctrostatic force for an ion-penetrable membrane is much smaller than t hat for an ion-impenetrable cell membrane. Under a fixed concentration of cations in the suspension medium, the rate of adhesion of the cell s increases with the Peclet number, aspect ratio and Hamaker constant.